Substituted 1-naphthyl n-methylcarbamate insecticide



United States Patent ice 3,197,354 snissrrrurnn rt rvrri rnvrcanea- METE QEIECTECHDE John F... Kilsheimer, South Charleston, W. V 21., andHerbert l i. Meoreiieid, Raleigh, Null, assignors to Union Ca bideCorporation, a corporation of New York No Drawing. @riginal applicationDec. 3%, was, Ser. No. 79,523, new Fatent No. 3,099,681, dated July 38,1963. Divided and this application Apr. 26, 1963, Ser. No. 236,482

6 Claims. (or. rev-4,2 10

wherein R is a lower alkyl radical. Particularly preferred are thecompounds wherein said alkyl radical contains up to 5 carbon atoms.Examples of such compounds include l-(S-acetarnidonaphthyl)N-methylcarbamate, 1-(5- propionamidonaphthyl) N-methylcarbamate,I-(S-butyramidonaphthyl) N- nethylcarbamate, l-(S-valeramidonaphthyl)N-methylcarbamate, l-(5-caproarnidonaphthyl) N-methylcarbamate, and t .elike.

The compounds of this invention can be prepared generally by reactingthe appropriate substituted l-naphthol 0 with phosgene in the presenceof a base to form the corresponding chloroformate. The chloroformate isthen reacted with monomethylamine to form the substituted l-naphthylN-methylcarbamate. This synthesis can be graphically represented by thefollowing equations:

Step A can be conducted at a temperature of from about -30 C. to about175 C. The reaction can be lated by adding phosgene dissolved intoluene, benzene, or other suitable organic solvent, to an aqueoussolution of the substituted naphthol and a base, preferably sodiumhydroxide. T he reaction is generally exothermic so that some externalcooling is usually necessary. This reaction can be conducted in thepresence of basic compounds 11 sodium hydroxide, such as pyridine anddimethylaniline, to facilitate removal of hydrogen chloride as anorganic hydrochloride. in these cases the reaction can be advantageouslyconducted in anhydrous solvents, such as toluene, dioxane and the like.

Step B can be conducted at a temperature of from about -3i C. to aboutC. The chloroformate can be added to a solution of methylamine in asolvent such as water, benzene, hexane, dioxane and toluene.

When the products are crystalline solids they can be separated from thereaction mixture by filtration or centrifugation and dried. In othercases the solvent is removed by distillation and the product is taken asa residue.

An alternate procedure for the preparation of the compounds of thisinvention is by the reaction of the appropriate substitute-d l-naplitholwith methyl isocyan-ate, as represented by the following schematicequation:

on o c oNnon cInNco I I r r r r ozo -r. o=o-n This reaction is conductedby reacting the appropriate naphthol with methyl isecyanate in thepresence of an anhydrous, inert solvent and a catalyst in a pressurevessel under autogenous pressure and at from about ambient temperaturesto about 260 C. The solvent is distilled oil from the reaction mixture,leaving as a residue the methylcarbamate. The catalyst can be anorganometallic compound such as dibutyl tin diacetate or an organictertiary amine such as pyridine. Applicable reaction solvents are ethylether, benzene, dioxane and the like. The methyl-carbamates canrecrystallized from solvents such as xylene, petroleum ether, benzene,methanol, and mixtures thereof.

The following examples are illust tion of the compounds of this invenive of the prepara- EXAMPLE I.-l- (5 -ACETAM1DONAPHTHY) I I-I/ZETZ'IYLCARBAMATE ?C ONHCH;

A mixture of 121 grams of 5-acetamido-1-naphthol, 3 grams of dibuty'ltin diacetate, and'SOO milliliters of dioxane Was charged to a reactionvessel and was heated at 25 C., after which 31.3 grams of methylisocyanate were added to the reaction mixture over a period of 30minutes. The resulting mixture was held at 25 C. with agitation forthree days, after which the dioxane 'was distilled oll. The solidresidue remaining in the reaction i3 vessel'was heated with methanol tothe boiling point and then cooled to 4G C. Crystals ofI-(S-acetamidonaphthyl) Namethylcarbamate that formed upon cooling werefiltered from the alcohol and dried. The crystals melted. at 212 C. andanalyzed as follows: N, 10.5 percent (calculated: N, 10.8 percent). Thestructure of the l-(S-acetamidonaphthyl) N-methylcarbamate was confirmedby infra-red analysis.

EXAMPLE H.l- S-BU'I'YRAMIDGNAPHTHYL) N-M ETHYLCARBAM ATE Employing theprocedure of Example I, I-(S-butyrarnldonaphthyl) N-methylcarbamate isprepared by reacting S-caproamido-l-naphthol with methyl isocyanate inthe presence of dioxane and dibutyl tin diacetate.

The compounds of this invention are useful as insecticides. They areparticularly eifective as insecticides against Mexican bean beetles andhouse flies, as is evidenced by the following tests.

A stock formulation of I-(S-acetamidonaphthyl) N- methylcarbamate wasprepared by mixing 100 mil ligrams of the compound with 10 millilitersof acetone and 10 milligrams of a dimeric alliylated aryl polyetheralcohol commercially sold as a wetting agent. This mixture was thendiluted with water to give 100 milliliters of the standard insecticidalsolution. Lower, graded, test concentrations were prepared by dilutingthe standard stock solution with water to give the desiredconcentration. The solutions, containing various concentrations in adilution series, were then tested on Mexican bean beetle larvae andhouse flies. Percent mortality of the test insects was plotted againstthe toxicant concentration on logarithmic probability paper. Theconcentration in milligrams of toxicant per 100 milliliters of solutionneeded for 50 percent mortality (LD value) is interpolated from a L nedrawn through the points so plotted.

Mexican beam beetle lea] dip test The test insects were fourth instarlarvae of the Mexican bean beetle (Epilachna varivestis Muls.) that hadbeen reared on Tendergreen beans at a temperature of 80 F: 5 F. and arelative humidity of 50 percent-:5 percent. Four randomly selectedlarvae were placed in a 9-cm. Petri dish containing a leaf of aTendergreen bean plant. The leaves were prepared by excising paired seedleaves from the bean plants and dipping the excised leaves in testsolutions prepared according to the above directions until thoroughlywetted. Excess liquid was removed from the surface of the leaf by gentleshaking. The leaves were then dried in a ventilated hood. Wilting of theleaves during drying was prevented by placing the leaf stems in water.The dried, paired leaves were then separated and a single leaf wasplaced in a Petri dish lined with filter paper. After placing the leafand larvae in the Petri dishes, the dishes were closed, labeled, andheld at 80 F. to 85 F. for three days. Although the larvae could easilyconsume the whole leaf within twenty-four to forty-eight hours, noadditional leaves were added. Larvae exposed to untreated leavesremained vigorous during the entire holding period and did not advanceto the quiescent prepupal state. Larvae which were unable to move thelength of the body, even upon prodding, were considered dead.

Fly bait test The test insects were four to six-day old adult houseflies (Musca domestica L.) that were reared according to thespecifications of the Chemical Specialties Manufacturing Association[Blue Book, MacNair-Dorland Company, New York, pages 24%244, 261(1954)], at a temperature of 80 F.:2 F. and a relative humidity of 50percentiS percent. The adult flies were anesthetized with carbon dioxideand twenty-five of such flies were placed under a hemispherical wirecage approximately 5 inches in diameter and 3 inches high, which wasinverted t over a sheet of white blotting paper measuring six inches bysix inches on which was placed a bait cup containing a one-inch squarepad of commercially available cellulose absorbent material.

Fifteen milliliters of a test formulation prepared as described above,to which had also been added 10 percent by wei ht of sugar, was added tothe bait cup. The llies were kept at a temperature of F.i5 F. and arelative humidity of 50 percentiS percent for twenty-four hours. Flieswhich showed no sign of movement on prodding after the twenty-four hourperiod were considered dead.

The results of the above-described tests are set forth in Table 1 below.

From Table I it can be seen that 1-(5-acetamidonaphthyl)N-methylcarbamate is insecticidally active toward the Mexican beanbeetle and house flies. Furthermore, the compounds of this invention arestable in the presence of light and air.

The compounds of the instant invention can be applied to plants or otherareas to be protected. by contacting such area with a compound of theinstant invention in an undiluted form, as a dust when admixed withfinely powdered inert carriers, or in a liquid form. The rate ofapplication can vary from about 0.5 to about 5 pounds of the compoundper acre.

When the compounds of the instant invention are applied as dusts theycan be mixed with suitable particulate extenders, such as clay, chalk,talc, diatomaceous earth, pyrophyllite, infusorial earth, fullers earth,pumice, bentonite, and Hours, such as cotton seed flour and walnut shellflour.

The application of the instant compounds in a liquid medium can beaccomplished in any of several ways. For example, a compound of thisinvention can be diectly dispersed in a liquid carrier such as water,petroleum distillates and the like with or without the use of surfaceactive agents.

Another method of preparation of liquid compositions containing thecompounds of this invention is to first prepare a liquid concentratecontaining such components by dissolving said compound in a solvent suchas acetone, toluene, xylene or kerosene. This liquid concentrate canthen be added to water together with suitable surface active dispersingagents whereby the compounds of the instant invention are dispersed inthe water.

A third method of preparing liquid compositions containing the instantcompounds is to prepare a wettable powder by dispersing said compoundson or in a finely divided inert solid such as clay, talc, chalk,bentonite, fullers earth and the like. These compositions may alsocontain dispersing or wetting agents as desired. These compositions canthen be mixed with water to provide a liquid insecticide suitable forapplication to the areas to be treated.

The surface active agents that can be employed in the above-describedcompositions can be any of the known anionic, cationic and non-ionicwetting, emulsifying and dispersing agents, such as aralkyl polyetheralcohols,

aralkyl polyether sulfonates, aralkyl polyether sulfates,

quaternary ammonium compounds and the like. When these surface activeagents are employed they generally comprise from about 0.5 percent toabout 5 percent by weight of the total composition.

We claim: 1. An insecticidal composition comprising a compound havingthe structural formula:

0C ONHCHa (I)CONHCH O=(I}R wherein R is lower alkyl radical to a locusto be protected. 4. The process for killing insects which comprisesapplying an insecticidal amount of I-(S-acetamidonaphthyl)N-methylcarbamate to a locus to be protected.

5. The process for killing insects which comprises applying aninsecticidal amount of a compound having the structural formula:

('IJCONHOHa O=( .l-R

wherein R is a lower alkyl radical to said insects.

6. The process for killing insects which comprises applying aninsecticidal amount of I-(S-acetamidonaphthyl) N-rnethylcarbamate tosaid insects.

References Cited by the Examiner UNITED STATES PATENTS 2,493,710 1/50Aeschlimann et a1.

2,776,197 1/57 Gysin et a1. 2,903,478 9/59 Lambreck. 2,904,464 9/59Moorefield. 2,904,465 9/59 Moorefield.

3,037,993 6/62 Shulgin.

FOREIGN PATENTS 578,169 6/59 Canada.

JULIAN S. LEVI'IT, Primary Examiner.

5. THE PROCESS FOR KILLING INSECTS WHICH COMPRISES APPLYING ANINSECTICIDAL AMOUNT OF A COMPOUND HAVING THE STRUCTURAL FORMULA: